1. Field of the Invention
The present invention relates to a knocking detector for detecting the occurrence of knocking from the vibration of an internal combustion engine.
2. Description of the Prior Art
A method of detecting the occurrence of knocking in an internal combustion engine is known in the art in which knocking is detected from the vibration of the engine. This method makes use of the fact that when knocking occurs, the vibration due to the combustion chamber pressure causes a mechanical vibration in the parts of the engine. Pressure vibrations due to knocking of the ordinary automobile engines fall within the range of 5 to 15 KHz, and the value of vibration is substantially constant according to the type of an engine. Consequently, by detecting the vibration with a vibration detector, it is possible to detect the knocking. However, due to the fact that an engine body involves vibration factors due to the combustion and movement of the engine parts, in order to detect the occurrence of knocking (i.e., to detect the vibration due to knocking), it has been necessary to deal with the knocking vibration frequency band by an electrical circuit comprising a band-pass filter or the like.